In a known plate heat exchanger, portions of a passage formed between adjacent ones of heat transfer plates are sealed near an inlet and an outlet for a fluid (see Patent Literature 1).
In another plate heat exchanger, the positions of an inlet and an outlet for a fluid are changed and sealed portions are provided so as to avoid the stagnation of the fluid in the plate heat exchanger and the freezing of the fluid in the plate heat exchanger (see Patent Literature 2).
In yet another plate heat exchanger, waves extend from a position near each of an inlet and an outlet in such a manner as to be substantially parallel to one another and at regular intervals, or waves extend radially with respect to the short-side center line of the plate (see Patent Literature 3).